Why did colonists reject the Albany Plan of Union?

The Albany Plan of Union was a plan to create a unified government for the Thirteen Colonies, suggested by Benjamin Franklin, then a senior leader (age 45) and a delegate from Pennsylvania, at the Albany Congress on July 10, 1754 in Albany, New York. More than twenty representatives of several northern and mid-Atlantic colonies had gathered to plan their defense related to the French and Indian War, the front in North America of the Seven Years' War between Great Britain and France. The Plan represented one of multiple early attempts to form a union of the colonies "under one government as far as might be necessary defense and other general important purposes.